Common knowledge; Invisible Mountain;; Discrimination series -P.17

After conquering, the Rounds instilled into the Triangles by repetition,
"You are a barbaric inferior race."
As the outcome, the Triangles also started to believe that they themselves were an inferior race
and regard the Rounds as their masters and beings like gods.

"The Triangles are an inferior race and the Rounds are more advanced, a superior race";
gradually this fantasy became common sense shared by most of people on this planet.